Shipwreck yields tonnes of silver coins

The sunken treasure, and the way it was recovered, has re-opened the debate about who owns history (Image: iStockphoto)

Treasure hunters who have retrieved 17 tonnes of silver coins from a shipwreck in the Atlantic say the find is the largest of its kind and worth hundreds of millions of dollars.

Odyssey Marine Exploration, a US company that specialises in deep-sea exploration, says the coins and other artefacts were found on a colonial period wreck in the Atlantic Ocean.

But it is not revealing the exact location, citing security and legal reasons.

The Spanish government is reportedly investigating the circumstances surrounding the exploration.

The artefacts include over 500,000 silver coins weighing more than 17 tonnes, hundreds of gold coins, as well as worked gold, says the Florida-based company.

"It is believed that this recovery constitutes the largest collection of coins ever excavated from a historical shipwreck site," according to the company, which says it used a tethered underwater robot, or remotely operated vehicle, in the salvage operation.

The find is expected to trigger the long-running debate between deep-sea explorers and maritime archaeologists, reports the New York Times.

It says Kevin Crisman, an associate professor in the nautical archaeology program at Texas A&M University, describes commercial exploration of shipwrecks as "theft of public history and world history".

But the company says it has used archaeological protocols to explore and document the find.

"We have treated this site with kid gloves and the archaeological work done by our team out there is unsurpassed. We are thoroughly documenting and recording the site, which we believe will have immense historical significance," says John Morris, Odyssey's co-founder and chief executive.

Secret location

The company is guarding information about the site and identity of the shipwreck, which it code-named Black Swan.

"For site security and legal reasons, we are not prepared to give the location, depth or any other information about the site," the company says, adding that it plans further excavations once it has confirmed the name and nationality of the sunken ship.

"We have some interesting evidence that tends to point to a specific shipwreck, but we do not intend to discuss this publicly until we have had a chance to review contemporary records and conduct extensive analysis of the artefacts and coins that have been recovered to date," Odyssey says.

The company makes it clear it wants to assert its legal rights to the find before it would provide details of its location, but insists the shipwreck is well beyond any country's territorial waters.

Earlier this week, a US court granted Odyssey ownership of the contents of a sunken ship located 100 metres below the surface and 64 kilometres off Land's End, off the southerwestern tip of England.

The wreck is believed to be of a 17th century merchant ship.

Coins to be restored

The company says the coins have been shipped to the US for restoration.

"The remarkable condition of most of the first 6000 silver coins conserved has been a pleasant surprise, and the gold coins are almost all dazzling mint state specimens," says Greg Stemm, Odyssey's chief executive officer.

"We are excited by the wide range of dates, origins and varieties of the coins, and we believe that the collecting community will be thrilled when they see the quality and diversity of the collection."

Historical shipwrecks are of great interest to marine archaeologists because of the information they can yield about seafaring, warfare and social life of the period in which the ship sank.